What version of the software are you using on the H90? When was the last time you updated? You can check this in the system menu under “about.”
I don’t know why using batteries in the outboard overdrive pedals would affect the behavior of the H90, especially since the H90 is powered by its own adapter. It is true the H90 should not be disconnecting from H90 Control for any reason. Are you on a Mac or PC?
Regarding pedal calibration, always make sure to connect to the expression pedal first, then to the EXP inputs. This way the pedal senses the proper load. In the system menu, under “I/O,” when you go into the calibration mode and Rock the pedal back and forth, you cannot get it to sweep from zero to 100? Are you using a TRS expression pedal with the right cable? Does the expression pedal have a 10K-25K linear potentiometer?
